1. Field of the Invention
The present invention relates to a battery pack spacer and a battery pack. Specifically, the invention relates to: a battery pack spacer and a battery pack, the battery pack spacer being capable of suppressing contact between terminals of single cells constituting the battery pack when a load of higher than the withstand load of the battery pack is applied from the outside to the battery pack.
2. Description of Related Art
The importance of a battery pack, which is constructed by connecting plural single cells to each other in series or in parallel, has increased as a power supply, for example, a vehicle-mounted power supply or a power supply for a PC, a portable device, or the like, the single cell being a storage element such as a secondary battery (for example, a lithium ion secondary battery or a nickel metal hydride battery) or a capacitor. In particular, a battery pack constructed by connecting plural light-weight lithium ion secondary batteries having high energy density as single cells to each other in series is preferably used as a vehicle-mounted power supply with high output.
Examples of prior art documents relating to a lithium ion secondary battery (single cell) include Japanese Patent Application Publication No. 2006-128120 (JP 2006-128120 A) and Japanese Patent Application Publication No. 2013-98137 (JP 2013-98137 A). JP 2006-128120 A discloses a cylindrical lithium ion secondary battery. JP 2013-98137 A discloses a flat lithium ion secondary battery. Further, examples of prior art documents relating to a battery pack in which lithium ion secondary batteries are used include Japanese Patent Application Publication No. 2006-48996 (JP 2006-48996 A) and Japanese Patent Application Publication No. 10-112301 (JP 10-112301 A). JP 2006-48996 A and JP 10-112301 A disclose a battery pack which is constructed by arranging a spacer plate (battery pack spacer) having high heat dissipation between single cells constituting the battery pack, for example, in order to cool the single cells.
In a battery pack which is used in, for example, a vehicle-mounted power supply, a situation is assumed in which a high load of higher than the withstand load of the battery pack is applied to the battery pack, for example, due to an automobile accident. In this way, when a part of single cells and battery pack spacers constituting the battery pack are damaged or deformed by a high load being applied from the outside to the battery pack, there may be contact between a terminal (positive electrode terminal or negative electrode terminal) of one single cell and a terminal (negative electrode terminal or positive electrode terminal) of another single cell adjacent to the single cell. The contact between the terminals is likely to occur, in particular, when a high load is applied to the battery pack in a single cell arrangement direction from at least one outside.
Contact between terminals of single cells causes short-circuiting of a battery, which is not preferable. Therefore, the creation of a technique is required which is capable of favorably preventing or suppressing contact between terminals of single cells even in a case where a battery pack is damaged or deformed by a high load of higher than the withstand load of the battery pack being applied to the battery pack.